The comparative biochemistry, enzymology and mechanism of action of acid phosphatase isoenzymes are being studied. Under study are human prostatic and human liver acid phosphatase, and isoenzymes of rat liver and bovine liver acid phosphatase. The biochemical and structural properties of the homogeneous enzymes are being studied. The mode of interaction of the transition state analogs tungstate, vanadate and molybdate with the enzymes are being examined. Phsophate water oxygen exchange catalyzed by prostatic acid phosphatase is being studied.